KINETICS OF THE INITIAL REACTION BETWEEN AN ALDEHYDE AND HYDROGEN PEROXIDE IN AQUEOUS SOLUTION

Five methods were proposed for analyzing the system under study. They are 1 determination of free AcH by titration using the NH2OH.HCl-NaOH, 2 spectrophotometric determination, 3 determination of free H2O2 by the perborate method, 4 polargraphic determination, and 5 calorimetric determination, methods 1 and 2 which were chosen for use in this investigation, are described in detail. It was found that with all 3 aldehydes the kinetic data were best fitted by assuming that the forward reaction is first order with respect to H2O2 and two-thirds order with respect to the aldehyde. A comparison is made of the values obtained from the chemical-analysis and the spectohotometric studies on AcH, HCHO, and EtCHO. The reaction with AcH is homogeneous, acid catalyzed, and does not involve free radicals under the conditions studied. The reaction rate increased in the order HCHO, AcH, EtCHO, and this was interpreted in terms of the degree of hydration of the 3 aldehydes. Observations on separation of partial oxidation products are interpreted in terms of the reactions studied.